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2019-04-08riscv: add support for multi-hart systemsLukas Auer
On RISC-V, all harts boot independently. To be able to run on a multi-hart system, U-Boot must be extended with the functionality to manage all harts in the system. All harts entering U-Boot are registered in the available_harts mask stored in global data. A hart lottery system as used in the Linux kernel selects the hart U-Boot runs on. All other harts are halted. U-Boot can delegate functions to them using smp_call_function(). Every hart has a valid pointer to the global data structure and a 8KiB stack by default. The stack size is set with CONFIG_STACK_SIZE_SHIFT. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-04-08riscv: save hart ID in register tp instead of s0Lukas Auer
The hart ID passed by the previous boot stage is currently stored in register s0. If we divert the control flow inside a function, which is required as part of multi-hart support, the function epilog may not be called, clobbering register s0. Save the hart ID in the unallocatable register tp instead to protect the hart ID. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-04-08riscv: delay initialization of caches and debug UARTLukas Auer
Move the initialization of the caches and the debug UART until after board_init_f_init_reserve. This is in preparation for SMP support, where code prior to this point will be executed by all harts. This ensures that initialization will only be performed once on the main hart running U-Boot. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-02-27riscv: generic: Ensure that U-Boot runs within 4GB for 64bit systemsAnup Patel
On 64bit systems, the DRAM top can be easily beyond 4GB and U-Boot DMA mapping APIs will generate DMA addresses beyond 4GB. This breaks DMA programming in 32bit DMA capable devices (such as Cadence MACB ethernet). For example, If DRAM is more then 2GB on QEMU sifive_u machine then Cadence MACB ethernet stops working for U-Boot because it is a 32bit DMA capable device. To handle 32bit DMA capable devices on 64bit systems, we provide custom implementation of board_get_usable_ram_top() which ensures that usable ram top is not more then 4GB. This in-turn ensures that U-Boot always runs within 4GB hence DMA addresses generated by DMA mapping APIs will be within 4GB too. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-02-27riscv: Rename cpu/qemu to cpu/genericAnup Patel
The QEMU CPU support under arch/riscv is pretty much generic and works fine for SiFive Unleashed as well. In fact, there will be quite a few RISC-V SOCs for which QEMU CPU support will work fine. This patch renames cpu/qemu to cpu/generic to indicate the above fact. If there are SOC specific errata workarounds required in cpu/generic then those can be done at runtime in cpu/generic based on CPU vendor specific DT compatible string. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-01-15riscv: move the AX25-specific implementation of flush_dcache_allLukas Auer
The fence instruction is used to enforce device I/O and memory ordering constraints in RISC-V. It can not be relied on to directly affect the data cache on every CPU. Andes' AX25 does not have a coherence agent. Its fence instruction flushes the data cache and is used to keep data in the system coherent. The implementation of flush_dcache_all in lib/cache.c is therefore specific to the AX25. Move it into the AX25-specific cache.c in cpu/ax25/. This also adds a missing new line between flush_dcache_all and flush_dcache_range in lib/cache.c. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2018-12-18riscv: Save boot hart id to the global dataBin Meng
At present the hart id passed via a0 in the U-Boot entry is saved to s0 at the beginning but does not preserve later. Save it to the global data structure so that it can be used later. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Return to previous privilege level after trap handlingBin Meng
At present the trap handler returns to hardcoded M-mode/S-mode. Change to returning to previous privilege level instead. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Fix context restore before returning from trap handlerBin Meng
sp cannot be loaded before restoring other registers. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Move trap handler codes to mtrap.SBin Meng
Currently the M-mode trap handler codes are in start.S. For future extension, move them to a separate file mtrap.S. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Do some basic architecture level cpu initializationBin Meng
In arch_cpu_init_dm() do some basic architecture level cpu initialization, like FPU enable, etc. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Update supports_extension() to use desc from cpu driverBin Meng
This updates supports_extension() implementation to use the desc string from the cpu driver whenever possible, which avoids the reading of misa CSR for S-mode U-Boot. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Remove non-DM version of print_cpuinfo()Bin Meng
With DM CPU driver, the non-DM version of print_cpuinfo() is no longer needed. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Probe cpus during bootBin Meng
This calls cpu_probe_all() to probe all available cpus. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: qemu: Add platform-specific Kconfig optionsBin Meng
Add the QEMU RISC-V platform-specific Kconfig options, to include CPU and timer drivers. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: ax25: Hide the ax25-specific Kconfig optionBin Meng
There is no need to expose RISCV_NDS to the Kconfig menu as it is an ax25-specific option. Introduce a dedicated Kconfig option for the cache ops of ax25 platform and use that to guard the cache ops. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Rick Chen <rick@andestech.com>
2018-12-18riscv: qemu: Create a simple-bus driver for the soc nodeBin Meng
To enumerate devices on the /soc/ node, create a "simple-bus" driver to match "riscv-virtio-soc". Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-05riscv: ax25-ae350: Pass dtb address to u-boot with a1 registerRick Chen
ax25-ae350 use CONFIG_OF_BOARD via a2 and CONFIG_SYS_SDRAM_BASE to boot from ram which allow the board to override the fdt address originally. But after this patch riscv: save hart ID and device tree passed by prior boot stage It provide prior_stage_fdt_address which offer a temporary memory address to keep the dtb address passing from loader(gdb) to u-boot with a1. So passing via a2 and CONFIG_SYS_SDRAM_BASE is redundant and can be removed. And it also somehow may corrupted BBL if it was be arranged in CONFIG_SYS_SDRAM_BASE. In board_fdt_blob_setup() When boting from ram: prior_stage_fdt_address will be use to reserved dtb temporarily. When booting from ROM: dtb will be pre-burned in CONFIG_SYS_FDT_BASE, if it is flash base. Or CONFIG_SYS_FDT_BASE maybe a memory map space (NOT RAM or ROM) which is provided by HW. Signed-off-by: Rick Chen <rick@andestech.com> Cc: Greentime Hu <greentime@andestech.com>
2018-12-05riscv: Add kconfig option to run U-Boot in S-modeAnup Patel
This patch adds kconfig option RISCV_SMODE to run U-Boot in S-mode. When this opition is enabled we use s<xyz> CSRs instead of m<xyz> CSRs. It is important to note that there is no equivalent S-mode CSR for misa and mhartid CSRs so we expect M-mode runtime firmware (BBL or equivalent) to emulate misa and mhartid CSR read. In-future, we will have more patches to avoid accessing misa and mhartid CSRs from S-mode. Signed-off-by: Anup Patel <anup@brainfault.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2018-11-26riscv: cache: Implement i/dcache [status, enable, disable]Rick Chen
AndeStar RISC-V(V5) provide mcache_ctl register which can configure I/D cache as enabled or disabled. This CSR will be encapsulated by CONFIG_RISCV_NDS. If you want to configure cache on AndeStar V5 AE350 platform. YOu can enable [*] AndeStar V5 ISA support by make menuconfig. This approach also provide the expansion when the vender specific features are going to join in. Signed-off-by: Rick Chen <rick@andestech.com> Cc: Greentime Hu <greentime@andestech.com>
2018-11-26riscv: save hart ID and device tree passed by prior boot stageLukas Auer
Store the hart ID and device tree passed by the prior boot stage (in a0 and a1) in registers s0 and s1. Replace one use of s1 in start.S to avoid overwriting it. The device tree is also stored in memory to make it available to U-Boot with the configuration CONFIG_OF_PRIOR_STAGE. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com>
2018-11-26riscv: do not blindly modify the mstatus CSRLukas Auer
The mstatus CSR includes WPRI (writes preserve values, reads ignore values) fields and must therefore not be set to zero without preserving these fields. It is not apparent why mstatus is set to zero here since it is not required for U-Boot to run. Remove it. This instruction and others encode zero as an immediate. RISC-V has the zero register for this purpose. Replace the immediates with the zero register. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com>
2018-11-26riscv: remove unused labels in start.SLukas Auer
The labels nmi_vector, trap_vector and handle_reset in start.S are not used for RISC-V. Remove them. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2018-11-26Drop CONFIG_INIT_CRITICALBin Meng
This is now deprecated and no board is using it. Drop it. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2018-11-26riscv: align mtvec on a 4-byte boundaryLukas Auer
The machine trap-vector base address (mtvec) must be aligned on a 4-byte boundary. Add the necessary align directive to trap_entry. This patch also removes the global directive for trap_entry, which is not required. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2018-11-26riscv: fix inconsistent use of spaces and tabs in start.SLukas Auer
start.S uses both tabs and spaces after instructions. Fix this by only using tabs after instructions. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com>
2018-10-03riscv: Move do_reset() to a common placeBin Meng
We don't have a reset method on any RISC-V board yet. Instead of adding the same 'unsupported' message for each CPU variant it might make more sense to add a generic do_reset function for all CPU variants to lib/, similar to the one for ARM (arch/arm/lib/reset.c). Suggested-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2018-10-03riscv: Add QEMU virt board supportBin Meng
This adds QEMU RISC-V 'virt' board target support, with the hope of helping people easily test U-Boot on RISC-V. The QEMU virt machine models a generic RISC-V virtual machine with support for the VirtIO standard networking and block storage devices. It has CLINT, PLIC, 16550A UART devices in addition to VirtIO and it also uses device-tree to pass configuration information to guest software. It implements RISC-V privileged architecture spec v1.10. Both 32-bit and 64-bit builds are supported. Support is pretty much preliminary, only booting to U-Boot shell with the UART driver on a single core. Booting Linux is not supported yet. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2018-10-03riscv: Make start.S available for all targetsBin Meng
Currently start.S is inside arch/riscv/cpu/ax25/, but it can be common for all RISC-V targets. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2018-10-03riscv: Add a helper routine to print CPU informationBin Meng
This adds a helper routine to print CPU information. Currently it prints all the instruction set extensions that the processor core supports. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2018-10-03riscv: Fix coding style issues in the linker scriptBin Meng
There are several coding style issues in the linker script. Fix them. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2018-10-03riscv: Move the linker script to the CPU root directoryBin Meng
The linker script can be shared by all RISC-V targets. Move it to a common place. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2018-08-20riscv: Include bss subsections in linker scriptAlexander Graf
When we build with -fdata-sections we may end up with bss subsections. Our linker script explicitly lists only a single consecutive bss section though. Adapt the statement to also include subsections. Signed-off-by: Alexander Graf <agraf@suse.de>
2018-07-25efi_loader: Rename sections to allow for implicit dataAlexander Graf
Some times gcc may generate data that is then used within code that may be part of an efi runtime section. That data could be jump tables, constants or strings. In order to make sure we catch these, we need to ensure that gcc emits them into a section that we can relocate together with all the other efi runtime bits. This only works if the -ffunction-sections and -fdata-sections flags are passed and the efi runtime functions are in a section that starts with ".text". Up to now we had all efi runtime bits in sections that did not interfere with the normal section naming scheme, but this forces us to do so. Hence we need to move the efi_loader text/data/rodata sections before the global *(.text*) catch-all section. With this patch in place, we should hopefully have an easier time to extend the efi runtime functionality in the future. Signed-off-by: Alexander Graf <agraf@suse.de> [agraf: Fix x86_64 breakage]
2018-05-29riscv: cpu: nx25: Rename as ax25Rick Chen
Andes has rearranged the product combinations. nx25 and ax25 both are RISC-V architecture cpu core. But ax25 has MMU unit inside, and nx25 is not. Cpu nx25 and platform ae250 are arranged in pairs. Cpu ax25 and platform ae350 are arranged in pairs. This patch will rename nx25 as ax25 ae250 as ae350 nx25-ae250 as ax25-ae350 including filename, variable, string and definition. Then u-boot can boot linux kernel in ae350 platform reasonably. Signed-off-by: Rick Chen <rick@andestech.com> Signed-off-by: Rick Chen <rickchen36@gmail.com> Cc: Greentime Hu <green.hu@gmail.com>
2018-05-29efi_loader: Enable RISC-V supportRick Chen
We have almost all pieces needed to support RISC-V UEFI binaries in place already. The only missing piece are ELF relocations for runtime code and data. This patch adds respective support in the linker script and the runtime relocation code. It also allows users to enable the EFI_LOADER configuration switch on RISC-V platforms. Signed-off-by: Alexander Graf <agraf@suse.de>
2018-05-07SPDX: Convert all of our single license tags to Linux Kernel styleTom Rini
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
2018-03-30riscv: ae250: Support DT provided by the board at runtimeRick Chen
Enable CONFIG_OF_BOAD to support delivery dtb to u-boot at run time instead of embedded. There are two methods to delivery dtb. 1 Pass from loader: When u-boot boot from RAM, gdb or loader can pass dtb via a2 to u-boot dynamically. Of course gdb or loader shall be in charge of dtb delivery. 2 Configure CONFIG_SYS_FDT_BASE: It can be configured as RAM or ROM base statically, no mater u-boot boot from RAM or ROM. If it was configured as ROM base, dtb can be burned into ROM(spi flash) by spi driver. Meanwhile remove CONFIG_SKIP_LOWLEVEL_INIT which is useless in nx25-ae250 configuration. Signed-off-by: Rick Chen <rick@andestech.com> Signed-off-by: Rick Chen <rickchen36@gmail.com> Cc: Greentime Hu <green.hu@gmail.com>
2018-01-12riscv: cpu: Add nx25 to support RISC-VRick Chen
Add Andes nx25 cpu core (called AndesStar V5) to support RISC-V arch Verifications: 1. startup and relocation ok. 2. boot from rom or ram both ok. 2. timer driver ok. 3. uart driver ok 4. mmc driver ok 5. spi driver ok. 6. 32/64 bit both ok. Detail verification message please see doc/README.ae250. Signed-off-by: Rick Chen <rick@andestech.com> Signed-off-by: Rick Chen <rickchen36@gmail.com> Signed-off-by: Greentime Hu <green.hu@gmail.com> Cc: Padmarao Begari <Padmarao.Begari@microsemi.com>